使用DistanceMatrixService.GetDistanceMatrix，得到「B」爲空或不是一個對象

Question

<script type=text/javascript src=https://maps.googleapis.com/maps/api/js? sensor=false></script> 
<script language=JavaScript> 
var mileageidx = new Number(); 
function getMileage(idx) 
{ 
    // code snipped 
    mileageidx = idx; 
    var service = new google.maps.DistanceMatrixService(); 
    service.getDistanceMatrix({ origins: [zipCode], destinations: [hostClubZipCode], travelMode: google.maps.TravelMode.DRIVING, unitSystem: google.maps.UnitSystem.IMPERIAL, avoidHighways: false, avoidTolls: false}, callback()); 
    // code snipped 
} 
function callback(response, status) 
{ 
    alert('in callback routine, mileageidx ='+mileageidx+' google status = '+status); 
    if (status == google.maps.DistanceMatrixStatus.OK) 
    { 
    var origins = response.originAddresses; 
    var destinations = response.destinationAddresses; 
    for (var i = 0; i < origins.length; i++) 
    { 
     var results = response.rows[i].elements;\n"; 
     for (var j = 0; j < results.length; j++)\n"; 
     { 
     var element = results[j]; 
     var distance = element.distance.text; 
     alert('distance='+distance); 
     var duration = element.duration.text; 
     var from = origins[i]; 
     var to = destinations[j]; 
     } 
    } 
    } 
    else 
    { 
    if (status == google.maps.DistanceMatrixStatus.INVALID_REQUEST) 
    { 
     alert('google.maps.DistanceMatrixStatus was INVALID_REQUEST'); 
    } 
    if (status == google.maps.DistanceMatrixStatus.MAX_ELEMENTS_EXCEEDED) 
    { 
     alert('google.maps.DistanceMatrixStatus was MAX_ELEMENTS_EXCEEDED'); 
    } 
    if (status == google.maps.DistanceMatrixStatus.OVER_QUERY_LIMIT) 
    { 
     alert('google.maps.DistanceMatrixStatus was OVER_QUERY_LIMIT '); 
    } 
    if (status == google.maps.DistanceMatrixStatus.REQUEST_DENIED) 
    { 
     alert('google.maps.DistanceMatrixStatus was REQUEST_DENIED'); 
    } 
    if (status == google.maps.DistanceMatrixStatus.UNKNOWN_ERROR) 
    { 
     alert('google.maps.DistanceMatrixStatus was UNKNOWN_ERROR'); 
    } 
    } 
} 

當代碼被執行時，得到消息「b」爲空或不是對象 DistanceMatrixService.getDistanceMatrix行1 代碼： 0 Char：1 URL：https://maps.googleapis.com/maps/api/js/DistanceMatrixService.GetDistanceMatrix?1m1&2s80 ...

此代碼工作兩次，然後開始給出此錯誤。

Answer 1

發現問題，它看起來代碼的兩部分在相同範圍內（例如相同的例程）有衝突。

當我將api移動到自己的例程中時，一切都開始奏效。 衝突/導致錯誤的代碼是：

xmlhttp.open(\"GET\",getClubURL,false); 
xmlhttp.send(); 
textToParse = xmlhttp.responseText; 

function calculateDistances(start,end) 
{ 
    //alert('Made it to calculateDistances'); 
    var service = new google.maps.DistanceMatrixService(); 
    alert('In calculateDistances, start is '+start+', end is '+end); 
    service.getDistanceMatrix(
    { 
    origins: [start], 
    destinations: [end], 
    travelMode: google.maps.TravelMode.DRIVING, 
    unitSystem: google.maps.UnitSystem.IMPERIAL, 
    avoidHighways: false, 
    avoidTolls: false 
    }, callback); 
} 

function callback(response, status) 
{ 
    if (status != google.maps.DistanceMatrixStatus.OK) 
    { 
    alert('Error was: ' + status); 
    } 
    else 
    { 
    var origins = response.originAddresses; 
    var destinations = response.destinationAddresses; 
    document.getElementById("mileage[mileageidx]").value = 
                response.destinationAddresses; 
    for (var i = 0; i < origins.length; i++) 
    { 
     var results = response.rows[i].elements; 
     for (var j = 0; j < results.length; j++) 
     { 
     var tmpTxt = new String(results[j].distance.text); 
     eos = tmpTxt.indexOf(' '); 
     alert('eos = '+eos); 
     tmpTxt = tmpTxt.substr(0,eos); 
     alert('tmpTxt is '+tmpTxt); 
     var miles = new Number(tmpTxt); 
     miles = Math.round(miles); 
     document.getElementById(\"mileage[\"+mileageidx+\"]\").value=miles; 
     } 
    } 
    } 
} // End of callback routine